Reversal color photographic processes

ABSTRACT

Color reversal processes comprising a negative silver development step, followed by reversal color development with an aqueous alkaline color developing composition containing a 3alkyl-N-alkyl-N-alkoxyalkyl-p-phenylenediamine or a 3-alkoxy-Nalkyl-N-alkoxyalkyl-p-phenylenediamine color developing agent advantageously produce color image reproductions that are superior to those produced by prior art processes by enhancing interlayer and intralayer interimage effects produced in the negative development step, thus giving more complete correction for unwanted absorptions of the dyes, as well as (1) reducing color contamination of dye images caused by color fog, (2) increasing the dye yield per unit of silver, (3) forming dyes of superior light stability, and (4) providing processes that are less sensitive to pH changes.

United States Patent Bent et al.

[ 51 Apr. 25, 1972 [72] Inventors: Richard L. Bent; Rowland G. Mowrey,both of Rochester, NY.

Eastman Kodak Company, Rochester, NY.

22 Filedz Dec. 3, 1970 [21] Appl.No.: 94,992

[73] Assignee:

[52] U.S. Cl. ..96/22, 96/55, 96/66 R,

2,552,242 5/1951 Weissberger et a]... 96/55 X 2,592,363 4/1952Weissberger et al... ..96/55 2,603,657 7/1952 Vinton ...96/66 R X2,716,132 8/1955 Martin "96/55 X 3,134,673 I 5/1964 Ganguin et al...96/66 R 3,265,502 8/1966 Wlllems et al Primary Examiner-Norman G.Torchin Assistant Examiner-Alfonso T. Suro Pieo Attorney-J. R.Frederick, R. C. Livermore and Robert W. Hampton [5 7] ABSTRACT Colorreversal processes comprising a negative silver development step,followed by reversal color development with an aqueous alkaline colordeveloping composition containing a3-alkyl-N-alkyl-N-alkoxyalkyl-p-phenylenediamine or a3-alkoxy-N-alkyl-N-alkoxyalkyl-p-phenylenediamine color developing agentadvantageously produce color image reproductions that are superior tothose produced by prior art processes by enhancing interlayer andintralayer interimage effects produced in the negative development step,thus giving more complete correction for unwanted absorptions of thedyes, as well as (1) reducing color contamination of dye images causedby color fog, (2) increasing the dye yield per unitof silver, (3)forming dyes of superior light stability, and (4) providing processesthat are less sensitive to pH changes.

16 Claims, No Drawings more efficient use of silver in REVERSAL COLORPHOTOGRAPHIC PROCESSES This invention is related to color photographyand more particularly to color photographic processing which givesproducing higher quality dye images.

' In the process of color photography, it is known to usepphenylenediamine developing agents in conjunction with couplers toproduce colored images. A summary of this process is described byThirtle et al., Encyclopedia of Chemical Technology, Vol. 5, pp. 812-845(1964), John Wiley & Sons, Inc. The color developing agent is oxidizedby the silver halide in the presence of a latent image in a photographicelement to produce silver metal and oxidized color developing agent. Theoxidized color developing agent then couples with colorproducingcompounds present to produce a dye image-wise with respect to silverdevelopment.

Color development of the differently sensitized emulsion layers in colorphotographic elements containing nondiffusible couplers isadvantageously performed in a single color development step to produce acolor negative image reproduction when this development step is thefirst development step, or to produce a color reversal image if anegative black-and-white development step followed by a step in whichthe residual unexposed and undeveloped silver halide is made developableand then color developed. In reversal color photographic elements thatdo not contain nondiffusible couplers, diffusible couplers are used inthe aqueous alkaline color developer solutions that are used toselectively color develop one silver halide emulsion layer at a time.The reversal processing of such a multicolor, multilayer element(containing no incorporated couplers) requires a negative blackand-whiteprocess followed by a step in which residual unexposed and undevelopedsilver halide in each emulsion layer is selectively made developable,then that layer is color developed with a color developing solutioncontaining a diffusible coupler that forms a nondiffusible dye that iscomplementary in color to the light-sensitivity of that layer, then theunexposed and undeveloped silver halide in a second emulsion layer isselectively rnade developable and color developed with another colordeveloping solution containing a diffusible coupler that forms anondiffusible dye that is complementary in color to thelight-sensitivity of that layer, then the unexposed and undevelopedsilver halide in the third emulsion layer is selectively madedevelopable and color developed with another color developing solutioncontaining a diffusible coupler that forms a nondiffusible dye that iscomplementary in color to the light-sensitivity of that layer. Followingcompletion of the color development, the silver and any residual silverhalide are removed by silver bleaching and then fixing the photographicelement.

It is known that interlayer and intralayer interimage effects areproduced during blackand-white development of a mul tilayer, multicolorelement containing silver bromoiodide emulsion layers in which at leastone layer contains at least one mole percent more iodide in mixed silverbromoiodide crystals than iodide in any mixed silver halide crystals inat least one of the other silver halide emulsion layers. The imagewisepattern of iodide ions released by development of the mixed silverhalide crystals containing the higher mole percent iodide diffuses tothe emulsion layer or emulsion layers that contain mixed silver halidecrystals containing a lower mole percent iodide and produces animage-wise inhibition of the latent image development resulting in anincrease in residual silver halide in the lower iodide-containing layeraccording to image development in the higher iodide containing layer.During subsequent color development, the increase in residual silverhalide that remained in the lower iodide-containing layer after negative(i.e., black-and-white) development, results in corresponding increasesin dye formation. It is known to utilize certain interimage effects toimprove color reproduction in subtractive color processes. Reference ismade to Journal of the Optical Society of America, 42, No. 9, pp.663-669. September l952,'wherein Hanson and Horton describe the use ofinterimage effects to correct for unwanted absorptions of photographicdyes. The term "mixed silver haalkyl-N-alkoxyalkyl-p-phenylenediaminecolor lide, e.g., silver bromoiodide, is to be distinguished from amixture of silver bromide and silver iodide. It is also known that thepresence of certain addenda, e.g., diffusible 4- thiazoline-Z-thiones inemulsion layers of a multilayer element during silver image developmentwill cause interimage effects.

Color development processes are desired which will enhance interimageeffects and give improved color reproduction.

Color development processes use active aromatic primary amine colordeveloping agents; however, not all silver halide grains containinglatent image centers are developed to silver and dye. These so-calleddead grains are wasted in color photographic development. Colordevelopment processes are desired that make more efficient use of latentimage-exposed silver halide grains so that the ratio of dye produced toexposed silver halide is larger than the ratio produced in processesknown before our invention.

Color development processes are desired that produce less fog or colordevelopment in non-image areas while they produce good dye densitylevels in image areas.

Color development processes are desired that are less sensitive to pHthan known processes.

Color development processes are also desired which produce dye imageshaving better stability to prolonged exposure to heat, high humiditiesand/or light. t

It is, therefore, an object of our invention to provide a novel colordevelopment process that produces an enhanced interimage effect.

Another object of our invention is to provide anovel color developmentprocess that produces improved color reproduction in subtractive colorprocesses as a result of enhanced interimage effects, as well as lowerfog in unexposed areas, higher dye densities in exposed areas, and acolor development process that is less sensitive to pH.

Another object of our invention is to produce a novel color developmentprocess that produces improved color reproduction by developingsubstantially all silver halide grains that contain latent images andleaving substantially no dead silver halide grains.

Still other objects will become apparent from consideration of thefollowing specification and claims.

The above and still other objects of our invention are ac complished byuse of our color photographic processes for treating an image-wiseexposed multicolor, multilayer photographic element comprising atransparent film support having coated thereon silver halide emulsionlayers sensitive to at least two of the red, green and blue areas of thevisible spectrum, preferably silver bromoiodide emulsion layers ofcamera speed. The silver halide emulsion layers are black-and-whitedeveloped to silver images in areas of exposure to produce interlayerand intralayer interimage effects. Such interlayer and intralayerinterimage effects are substantially enhanced in accordance with theinvention by color developing residual undeveloped silver halide in thepresence of photographic couplers to form nondiffusible dyessubstantially complementary in color to the light sensitivity of therespective silver halide emulsion layers in an aqueous alkaline colordeveloping composition containing a3-alkyl-N-alkyl-N-alkoxyalkyl-pphenylenediamine color developing agentor a 3-alkoxy-N- developing agent in which the several alkyl and alkoxygroups are lower alkyl and lower alkoxy groups. These color developingagents used according to our invention include those having the formula:

wherein n is an integer of 2 to 4; R is an alkyl group having one tofour carbon atoms, e.g., methyl, ethyl, propyl, butyl, etc.; and R' isan alkyl group having from one to four carbon atoms,

nun-m e.g., methyl, ethyl, propyl, butyl, etc., or an alkoxy grouphaving from one to four carbon atoms, e.g., methoxy, ethoxy, propoxy,butoxy, etc.

The photographic couplers present during the color development step areeither incorporated in the appropriately sensitized silver halideemulsion layer as nondiffusible couplers, in which case the colordevelopment of all three emulsion layers is advantageously accomplishedwith a single development step with one color developing solutioncontaining a 3-a1kyl-N-alkyl-N-alkoxyalkyl-p-phenylenediamine or a3-alkoxy-N-alkyl-N-a1koxyalkyl p-phenylenediamine color developingagent; or, diffusible couplers are used in developer solutions, forexample, a diffusible cyan-dye-forming coupler is used in a cyandeveloping composition to color develop the red-sensitive layer, adiffusible yellow-dye-forming coupler is used in a yellow developingcomposition to color develop the blue-sensitive layer and a diffusiblemagenta-dye-forming coupler is used in a magenta developing compositionto color develop the green-sensitive layer (of an element that containsno nondiffusible couplers) so that at least one of these colordeveloping compositions contains a3-a1kyl-N-a1kyl-N-a1koxyalkyLp-phenylenediamine or a3-alkoxy-N-alkyl-N-alkoxyalkyl-p-phenylenediamine color developingagent.

Black-and-white development is advantageously done with an aqueousalkaline composition comprising any non-dyeforming silver halidedeveloping agent, preferably at least one of hydroquinone,p-methylaminophenol, 1-phenyl-3- pyrazolidonc,4,4-dimethyl-3-pyrazolidone, etc.

Following the black-and-white development step, the undeveloped silverhalide is made developable by any appropriate means, such as, exposureto light, treatment with a chemical fogging agent, e.g., an alkali metalborohydride, an amine borane, etc., prior to or during the colordevelopment step. In processing a photographic element that requires thediffusible couplers in separate color developing solutions, the emulsionlayers after black-and-white development are sequentially treated in aselective way to make residual silver halide in one emulsion layer at atime developable and then color developed before silver halide inanother emulsion layer is made developable, etc. For example, in ablack-and-white developed photographic film having coated in successionon a transparent support a red-sensitive emulsion, a green-sensitiveemulsion, a bleachable yellow colored filter layer and a bluesensitiveemulsion layer, it is advantageous to selectively reexpose the bottomred-sensitive layer with red light through the support, cyan develop,wash, selectively re-expose the blue-sensitive layer directly with bluelight, yellow develop, wash, re-expose the middle green-sensitive layerwith white light or make this layer developable with a chemical foggingagentjust prior to or during magenta development.

Following completion of color development of the three emulsion layersin an element, the film is washed and the silver and any residual silverhalide is removed by treatment with a silver bleach followed by a fixingbath to leave the unobstructed multicolor dye image reproduction in thephotographic element. Conventional alkali metal ferricyanide bleachbaths and alkali metal thiosulfate fix baths are used advantageously tobleach and then fix the color developed elements.

Typical representative examples of the color developing agents ofFormula I are the following:

No. Color Developing Agent 1.N-Ethyl-N-methoxyethyl-3-methyl-p-pheny1enediamine 2.N-Ethyl-N-methoxybutyl-3-methyl-p-phenylenediamine 3.N-Ethyl-N-ethoxyethyl-3-methyl-p-phenylenediamine ylenediamine 6.N-Ethy1-N-butoxyethyl-3-methyl-p-phenylenediamine These and still otherdeveloping agents of Formula 1 are advantageously used as the free baseor as salts of organic or inorganic acids. For example, the hydrochloricacid salts, the sulfuric acid salts, the phosphoric acid salts, theoxalic acid salts, p-toluenesulfonic acid salts, the benzene disulfonicacid salts and the naphthalene disulfonic salts are used to advantage inour process.

The color developing agents of Formula I are used advantageously inaqueous alkaline color developer solutions over a wide range ofconcentrations, with an operable range of from about 0.5 g/] to about 15g/l and a preferred range of from about 1.0 g/l to about 12.0 g/l. Otheraddenda used to advantage in these developer compositions include alkalimetal chlorides, alkali metal bromides, alkali metal iodides, alkalimetal sulfites, alkali metal sulfates, alkali metal carbonates, alkalimetal hydroxides, alkali metal metaborates, a1- kali metal phosphates,ethylenediamine, citrazinic acid, antifogging agents, e.g.,S-nitrobenzimidazole, etc., an auxiliary developing agent, e.g., lphenyl-3-pyrazolidones, a stabilizer for developing agents (e.g.,diethyl hydroxylamine, dihydroxyacetone, glycolaldehyde, glyceraldehyde,dihydroxymaleic acid, etc., sodium hexametaphosphate, etc.), etc. Atypical color developing composition used in our process for aphotographic element that contains incorporated couplers is as follows:

Color Developing Composition 1 Benzyl alcohol 0-12 ml. Alkali metalhexametaphosphate O-3 g. Alkali metal sulfite 2-20 g. Tri alkali metalphosphate -l2H O l0-60 g.

Alkali metal bromide 0-5 g.

Alkali metal iodide (0.1% soln.) O-15 ml. Color developing agent ofFormula 1 05-15 g. Ethylenediamine sulfate 0-20 g. Citrazinic acid 0-5Dithiooctanediol 0-5 g.

Water to l 1.

and sufficient alkali, e.g., alkali metal hydroxide, alkali metalcarbonate, etc., to adjust the pH in the range of from about 10.0 toabout 14.0. The alkali metals used to advantage to make the compounds ofthe color developing composition are sodium, potassium, lithium, etc.Typical color developing compositions used to advantage in processes ofour invention for photographic elements that do not contain couplers areas follows:

Cyan and Yellow Color Developing Compositions In this composition, aphenol or naphthol cyan-die-forming coupler is used in cyan developingcompositions and an open chain acyl acetamide type yellow-dye-formingcoupler is used in yellow developing compositions. Antifoggants, suchas, 5- nitrobenzimidazole, 5-nitrobenzimidazole-6-nitrate, etc., areused to advantage as the antifoggant. Any ofthe alkalis used in photograhic developer solutions are used to advantage in the color developingcomposition including alkali metal hydroxides, alkali metal carbonates,borax, etc. The alkali metals used to advantage to make the compounds ofthe cyan and yellow color developing compositions and the followingmagenta color developing composition are sodium, potassium and lithium.

MAGENTA COLOR DEVELOPING COMPOSITIONS These are the same as the cyan andyellow developing compositions, except that they do not contain anauxiliary developing agent or any antifogging agent, but they do containin addition to the cOmponents listed above:

Alkali metal thiocyanate 0.3-5 g./l. Ethylenediamine LOO-8 m1./l. Achemical fogging agent for silver halide 0-2 g./l.

Chemical fogging agents used to advantage include the nucleating agentsof Hanson et al., U.S. Pat. No. 3,246,987, e.g., the amine boranes(e.g., trimethylamine borane, diethylamine borane, triethylamine borane,tert-butylamine borane, pyridine borane, 2,6-lutidine borane, etc.), thepolyamine boranes (.e.g, ethylenediamine diborane, hydrazine diborane,etc.), a phosphine borane (e.g., dimethylphosphine borane), an arsineborane (e.g., dimethylarsine borane), a stilbene borane (e.g.,dimethylstilbene borane a borazine (e.g., borazine, N,N',N-trimethylborazine, N,N,N"-trimethoxybora2ine, etc.). When no chemical foggingagent is used in the magenta color developing composition, a chemicalfogging bath is advantageously used just prior to the magenta colordeveloping composition or, alternatively, the unexposed green-sensitivesilver halide emulsion layer is made developable by exposure to light. Atypical chemical fogging bath has the composition:

Water to make Any of the chemical fogging agents listed above are uSedadvantageously in this composition.

Any of the well-known diffusible couplers used in the color developersolutions are used to color develop our photographic elements that donot contain incorporated couplers. These couplers include thosedescribed by U.S. Pat. Nos. 2,266,452, 2,295,009, 2,313,586, 2,362,598,2,369,929, 2,772,162, 3,002,836, 2,311,082, 2,353,205, 2,369,489,2,600,788, 2,343,703, 2,899,306, 2,115,394, 2,108,602, 2,113,330,2,271,238, 2,289,805, 2,439,352, etc.

The multicolor, multilayer color photographic elements processed toadvantage according to our invention are advantageously coated a a widevariety of transparent film supports including cellulose nitrate film,cellulose ester film, po1y(viny acetal) film, polystyrene film,poly(ethylene terephthalate) film, polycarbonate film and related filmsor resinous materials as well as glass. The redgreenand bluesensitivesilver halide emulsion layers are arranged in various orders on the filmsupports. In a preferred element, a red-sensitized silver halideemulsion layer is advantageously coated over the support, followed insuccession by a green-sensitized silver halide emulsion layer and ablue-sensitive silver halide emulsion layer. As has been mentionedbefore, one type of color photographic elements processed according toour invention contains a nondiffusible cyan-dye-forming coupler in thered-sensitized layer, a nondiffusible magenta-dye-forming coupler in thegreen-sensitized layer and a nondiffusible yellow-dye-forming coupler inthe blue-sensitive layer, while another type does not containnondiffusible couplers incorporated in the emulsion layers.Non-sensitive hydrophilic colloid interlayers are advantageously usedbetween one or more of the light-sensitive layers. It is advantageous tohave a bleachable yellow-colored filter between the blue-sensitive andgreen-sensitive layers.

Any of the hydrophilic colloids used in photographic elements areadvantageously used in the light-sensitive and non light-sensitivehydrophilic colloid layers of elements processed by our process.Hydrophilic colloids used alone or in combination include bothnaturally-occurring substances, (such as, proteins, e.g., gelatin,gelatin derivatives, etc., cellulose derivatives, polysaccharides, suchas, dextrose, gum arabic and the like) and synthetic polymericsubstances, such as, water-soluble polyvinyl compounds likepoly(vinylpyrrolidone), acrylamide polymers and the like.

Any of the ordinarily employed silver halide developing-out emulsions,e.g., silver chloride, silver chlorobromide, silver chlorobromoiodide,silver bromide, silver bromoiodide developing-out emulsions are used toadvantage in elements processed according to our invention. Particularlyuseful results are obtained with mixed silver halide emulsionscomprising an iodide, e.g., silver bromoiodide, silverchlorobromoiodide, silver chloroiodide, etc., containing mixed silverhalide crystals wherein the iodide comprises about 1 to about 20 molepercent of the halide of the mixed silver halide crystals. It isparticularly advantageous in photographic elements where interimageeffects are desired to have at least one silver halide emulsion layerwith mixed crystals having at least 1 mole percent'more iodide than anymixed silver halide crystals in at least one of the other silver halideemulsion layers; however, any silver halide emulsion can be usedprovided the emulsion in at least one layer differs from the emulsion inat least one other layer as to development rate and/or excess of halidein the silver halide.

In addition to, or instead of, the differences in the silver halideemulsion discussed above, certain addenda are advantageously used in oneor more of the silver halide emulsion layers to cause interlayer andintralayer interimage effects driving the black-and-white development.For example, diffusible 3-hydrogen substituted 4-thiazoline-2-thionesincludwherein X represents alkyl, e.g., methyl or ethyl, an alkylsubstituent containing at least one hydroxyl group, e.g., hydroxymethyl,B-hydroxyethyl, gluco or arabino, or an alkyl substituent having atleast one carbamyl-containing group, e.g., formyl, carboxyl, ethoxycarbonyl or acetoxy methyl; and Z is is independently selected from avalue given for X and preferably represents hydrogen. Advantageously,the 4- thiazoline-Z-thione compound is one which can enolize to itscorrespondingmercaptan form at any suitable time, such as, when the4-thiazoline-2-thione is added to a hydrophilic colloid layer containinglight-sensitive silver halide. Representative compounds include4-thiazoline-4-carboxaldehyde-2- thione,5-carbethoxy-4-methyl-4-thiazoline-2-thione,4-carboxy-4-thiazoline-2thione, 4-carboxy-5-methyl-4-thiazoline-2-thione, 4-(D-arabino-tetraacetoxybutyl)-4-thiazoline-2- thione,4-(D-arabino-l ,2,3,4-tetrahydroxybutyl)-4-thiazoline- 2-thione,4-hydroxymethyl-4-thiazoline-Z-thione, 4-methyl-4- thiazoline-2-thione.These compounds when in solution diffuse through hydrophilic colloidlayer of a photographic element in which they are incorporated or towhich they are applied in a processing solution prior to silver imagedevelopment or in the silver image developer itself. These compoundsform an immobile complex with silver halide in the emulsion layers andare released from silver halide grains as they are developed to silver.It is believed that the image-wise release of these compounds during thedevelopment of silver halide in one layer inhibits latent image silverhalide development in adjacent layers, thus causing undercut interimageeffects. Undercut interimage effects are characterized by repression ofa given color scale produced by a neutral exposure, and the lack of suchrepression for that color scale in a single color exposure. Undercutinterimage effects result in more saturated and brighter dye images andare advantageously measured by procedures described in articles such asby Hanson and Horton, Journal of the Optical Society of America, 42, No.9, pp. 663 669, September 1952 and Pinney, lnterimage Effects and ColorReproduction, The SPSE Reporter, November 1960.

The 3-hydrogen substituted 4-thiazoline-2-thiones are advantageouslyincorporated in silver halide emulsion layers in the range of from about5.0 mg to about 500 mg of the addenda per mole of silver and especiallyin the range of from 100 mg to 200 mg. When the 3-hydrogen substituted4- thiazoline-Z-thione is introduced into the emulsion in a solutionsuch as a black-and-white developer solution during photographicprocessing, a useful concentration range is from about 0.1 mg to about1.0 g per liter of solution and, preferably, in the range from about 1.0mg to 500mg per liter.

Interimage effects produced by any known method during theblack-and-white development are enhanced during the color development ofour process.

The silver halide emulsions used in elements processed according to ourinvention are advantageously spectrally sensitized with any of theappropriate cyanines, merocyanines, complex cyanines, complexmerocyanines, styryls, hemicyanines, etc. These dyes contain the usualbasic nuclei, e.g., thiazole, benzothiazole, naphthothiazole,benzoxazole, naphthoxazole, benzoselenazole, naphthoselenazole,quinoline, etc., or in the case of merocyanine dyes, an acidic nucleus,e.g., hydantoin, 2-thiohydantoin, oxazolidone, pyrazolone, etc. Suchdyes are described in the Brooker et al. U.S. Pat. Nos. 2,185,182,2,241,237; Carroll U.S. Pat. Nos. 2,635,961, 2,652,330; l-leseltine andBrooker U.S. Pat. No. 2,666,761; Carroll and Jones U.S. Pat. No.2,704,715; Brooker and White U.S. Patent No. 2,526,632; Sprague U.S.Pat. No. 2,503,776; Brooker et al. U.S. Pat. No. 2,493,748 and Taber etal., U.S. Pat. No. 3,384,486.

Photographic silver halide emulsions, such as those listed above, canalso contain such addenda as chemical sensitizers, e.g., sulfursensitizers (e.g., allyl thiocarbamide, thiourea, allylisothiocyanate,cystine, etc.), various gold compounds (e.g., potassium chloroaurate,auric trichloride, etc.) (see Baldsiefen, U.S. Pat. No. 2,540,685;Damschroder, U.S. Pat. No. 2,597,856 and Yutzy and Leermakers, U.S. Pat.No. 2,597,915 various palladium compounds, such as, palladium chloride(Baldsiefen et al., U.S. Pat. No. 2,540,096), potassium chloropalladate(Stauffer et al. U.S. Pat. No. 2,598,079), etc., or mixtures of suchsensitizers; antifoggants, such as, ammonium chloroplatinate (Trivelliand Smith, U.S. Pat. No. 2,566,245), ammonium chloroplatinite (Trivelliand Smith, U.S. Pat. No. 2,566,263), benzotriazole, nitrobenzimidazole,S-nitroindazole, benzidine, mercaptans, etc. (see Mees, The Theory ofthe Photographic Process, Macmillan Pub., 1942, p. 460), or mixturesthereof; hardeners, such as, formaldehyde or chrome alum (Miller U.S.Pat. No. 1,763,533), glyoxal (Brunken, U.S. Pat. No. 1,870,354),dibromacrolein (Bloch et a1, British Pat. No. 406,750), aziridinehardeners of Burness, U.S. Pat. No. 2,964,404; Allen ct al., U.S. Pat.No. 2,950,197; Yudelson, U.S. Pat. No. 3,017,280, oxazolium hardeners ofVanCampen et al., US. Pat. No. 3,316,095, Burness et al., U.S. Pat. No.3,321,313, vinyl sulfone hardener of Belgian Pat. No. 686,440, etc.

Any of the color-forming couplers used in photographic elements are usedto advantage in photographic materials for our process. lncluded amongthe phenol and naphthol cyan dyel orming couplers used to advantage arethose described by the following U.S. Pat. Nos. 2,423,730, 2,474,293,2,521,908, 2,725,291, 2,801,171, 3,253,294, etc. lncluded among theketomethylene yellow-dye-forming couplers used to advantage are thosedescribed in U.S. Pat. Nos. 2,298,443, 2,778,658, 2,801,171, 2,875,057,3,253,924, 3,277,155, etc. lncluded among the 5-pyrazolone magentadye-forming couplers used to advantage are those described in U.S. Pat.Nos. 2,600,788, 2,801,171, 3,252,924, etc.

Dispersing agents for color-forming couplers and the dispersingtechniques used to advantage include those set forth in Jelley et al.,U.S. Pat. No. 2,322,027; Mannes et al., U.S. Pat. No. 2,304,940; Fierkeet al., U.S. Pat. No. 2,801,l7l,etc.

In general, the color developing agents of Formula I are prepared byreacting the appropriate w-alkoxyalkyl chloride or bromide with theappropriate N-ethyl-3-alkylaniline or N- ethyl-3-alkoxyaniline. Thetertiary anilines formed by this reaction are then either nitrosated orazo-coupled, followed by catalytic hydrogenation to give thecorresponding p-phenylenediamines. Some of the developing agents ofFormula 1 are advantageously isolated as the acid salts.

The di-p-toluenesulfonic acid salt of Color Developing Agent 3 isadvantageously prepared by the following sequence of reactions:

(1) N-(B-Ethoxyethyl)-N-ethyl-3-methylani1ine: A mixture of g (1 mole)of N-ethyl-3-methylaniline, 153 g (1 mole) of 2-bromoethyl ethyl ether(purified by treatment with sodium bicarbonate and distillation), 88.2 g(1.05 mole) of sodium bicarbonate, 1,100 ml of ethanol and 290 ml ofwater are refluxed for a total of 64 hours. The ethanol is removed bydistillation and the oil layer is extracted with ether; the etherextracts are dried and concentrated, followed by distillation of theresidual oil under reduced pressure. After removal of the lower boilingforeruns, the fraction, b.p. 9295 C/lmm (overheats readily), iscollected. The yield of l is approximately 70 percent.

(ll) 4-(2,5-Dichlorophenylazo)-N-(,B-ethoxyethyl)-N-ethyl-3-methylaniline: A total of 44 g (0.27 mole) of 2,5- dichloroaniline isdissolved in a mixture of 240 ml concentrated hydrochloric acid and 700ml of water by heating with stirring on a steam bath. When solution iscomplete, the reaction mixture is cooled with stirring to 5 C, thehydrochloride salt precipitating out. A solution of 19 g (0.275 mole) ofsodium nitrite in 75 ml of water is added dropwise with stirring,keeping the temperature at about 5 C. When complete, stirring iscontinued for another 20 minutes and the excess nitrous acid destroyedby the addition of sulfamic acid. The cold diazonium solution isfiltered and at once added to a cold solution of 56 g (0.27 mole) ofl indilute hydrochloric acid. Considerably more water is added and withstirring a total of 250 g of sodium acetate is added to promote thecoupling. After standing for a few hours, the azo dye is filtered offand at once recrystallized from approximately 1,000 ml of ethanol. Thisis followed by a second recrystallization from 900 ml of ethanol,filtering hot and cooling to about 25 C. The yield of 11, mp. 74.5 75.5C, is 77 percent.

4-Amin0-N-(,B-ethoxyethyl)-N-ethy1-3-methylaniline, di-ptoluenesulfonicacid salt (Developing Agent 3): Three grams of the azo dye, 11, isreduced on a Parr shaker using 300 ml of absolute alcohol and Raneynickel as catalyst. When complete, the catalyst is filtered off andwashed on funnel with more ethanol. A solution of 3 g (0.0158 mole) ofp-toluenesulfonic acid (hydrate) in 50 ml ethanol is added and thesolution is then concentrated to dryness (partial vacuum). The semisolidis then slurried thoroughly with 35 ml of hot isopropyl alcohol,gradually becoming nicely crystalline. The mixture is cooled to about 25C and allowed to stand undisturbed overnight. The developer salt isfiltered off and washed in funnel with small portions of isopropylalcohol. The yield of Developing Agent 3, mp. 2l4216 C, is approximately70 percent.

The di-p-toluenesulfonic acid salt of Color Developing Agent 5 isadvantageously prepared similarly to developing agent (3), usingN-ethyl-3-methoxyaniline and 2-bromoethyl methyl ether as startingmaterials.

(III) N-Ethyl-3-methoxy-N-(B-methoxyethyl)-aniline: A mixture of 100 g(0.661 mole) of N-ethyl-3-methoxyaniline, 92 g (0.661 mole) of2-bromoethyl methyl ether, 55.8 g (0.6665 mole) of sodium bicarbonate,1,000 ml of ethanol and 280 ml of water is refluxed for a total of 68hours. The alcohol is removed under partial vacuum and the oil layerextracted with ether; the ether extracts are dried and concentrated. Theresidual oil is then distilled under reduced pressure. The yield of ill,b.p. l49-l5 1 C/8mm, is 35 percent.

(IV) 4-(2,5-Dichlorophenylazo)-N-ethyl-3-methoxy-N-(,B-methoxyethyl)aniline: This azo dye is prepared from III in exactly thesame way as described for the preparation of the azo dye used fordeveloping agent (3). The yield of IV, m.p. 94- 96 C (from ethanol), isapproximately 73 percent.

The di-p-toluenesulfonic acid salt of 4-amino-N-ethyl-3-methoxy-N-(B-methoxyethyl)aniline Developing Agent 5'): Exactly 486 g(0,127 mole) of the azo dye, IV, is reduced on Parr shaker, using 300 mlof absolute alcohol and Raney nickel as catalyst. When complete, thecatalyst is filtered off, washed on funnel with more alcohol. A total of4,84 g (0.0254 mole) of p-toluenesulfonic acid (hydrate) in 50 ml ofethanol is added; no precipitate occurs and the solution is concentratedto dryness under partial vacuum. The gummy residue is then dissolved ina small quantity of absolute alcohol and a large excess of ethyl etheris added; the developer salt again comes out as a gum; the solution iscooled thoroughly (refrigerator) to precipitate the suspension and thenthe etheralcohol layer is decanted. This treatment is repeated twicemore to remove all of the regenerated 2,5-dichloroaniline. Finally, thedeveloper salt is slurried thoroughly with ether only, graduallybecoming crystalline; it is dried in a vacuum oven. The yield ofDeveloping Agent 5, mp. l60l62 C, is 62 percent.

The di-p-toluenesulfonic acid salt of Color Developing Agent 1 is madein a manner similar to the synthesis described for the correspondingacid salt of Color Developing Agent 5, excepting that an equimolaramount of N-ethyl-3- methylaniline is used in place ofN-ethyl-3-methoxyaniline.

The di-p-toluenesulfonic acid salt of Color Developing- Agent 2 is madein a manner similar to the synthesis described for the correspondingacid salt of Color Developing Agent 5, excepting that an equimolaramount of arbromobutyl methyl ether is used in place of 2-bromoethylmethyl ether.

The di-p-toluenesulfonic acid salt of Color Developing Agent 4 isadvantageously made in a manner similar to that described for thecorresponding acid salt of Color Developing Agent 3, excepting that anequimolar amount of N-ethyl-3- propylaniline is used in place ofN-ethyl-3-methylaniline.

Still other color developing agents of Formula I are made using thesyntheses illustrated herein using the appropriate intermediates.

The following examples are included for a further un derstanding of ourinvention:

Example 1 Two samples of a multilayer color film having a celluloseacetate film support coated in succession with a red-sensitive gelatinosilver bromoiodide emulsion layer, a green-sensitive gelatino silverbromoiodide emulsion layer, a gelatin layer containing bleachable yellowcolored Carey Lea silver and a blue-sensitive gelatino silverbromoiodide emulsion layer are sensitometrically exposed to a steptablet and processed at 27 C through the following process sequence:

Red light exposed through support Cyan developing composition 4 min. 30sec.

Water wash 7 2 min. Blue light exposed through emulsion Yellowdeveloping composition 4 min. Water wash 2 min.

Borohydride bath 1 min.

Water wash 30 sec. Magenta developing composition 5 min. 30 sec. Waterwash 4 min. Ferricyanide bleach 2 min.

Hypo fix bath 2 min.

Water wash 4 min.

Dry

The solutions used have the compositions given below:

Prehardener Sodium hexametaphosphate Sulfuric acid Sodium tetraborate-5I-l O Sodium bromide Sodium sulfate Formalin (37.5%) Sodium bisulfiteWater to make MQ Negative Developing Composition Sodiumhexametaphosphate' Sodium sulfite Monomethyl-p-aminophenol sulfateSodium hydroxide Hydroquinone Sodium carbonate Potassium iodide (0.1%)Sodium bromide Sodium thiocyanate Hydroquinone monosulfate Water to makeYellow Developing Composition Sodium hexametaphosphate Sodium sulfiteSodium bromide Polyoxyethylene (m.wt. 4000) Potassium iodide (0.1%soln.) Color developing agent S-Nitrobenzimidazole l.% soln.) Sodiumhydroxide Sodium sulfate Hexylene glycol An a-pivalyl-acetanilide Yellowdye-forming coupler) Diethyl hydroxylamine l -Phenyl-5-pyrazolidoneWater to make pH at 27 C.=l2.0

rQ-P pouPo some 5 BWWW' Film Sample I is yellow developed in the yellowdeveloping composition having 1.06 g/l of Color Developing Agent B,i.e., N-ethyl-N(B-hydroxyethyl)-3-methyl-p-phenylenediamine and FilmSample II is yellow developed in the yellow developing compositionhaving 2.0 g/l of Color Developing Agent 1, i.e.,N-ethyl-N-methoxyethyl-3-methyl-p-phenylenediamine.

Borohydride Bath Sodium hexametaphosphate 0.6 g.

Sodium hydroxide 2.16 g. Potassium borohydride 0.10 g. Water to make 1liter Sodium hexametaphosphate 4.0 g. Sulfuric acid 2,] 1, Sodiumphosphate -l2H O 40.0 g. Sodium sulfite 5.0 g. Sodium thiocyanate 1.0 g.Potassium iodide (0.1%) 7.5 ml. Sodium bromide 0.5 g. Sodium sulfate60.0 g. 4Amino-N-ethylN-B-hydroxyethy1-3- methylaniline sulfate 2.9 g.Citrazinic acid 0.72 g. Ethylenediamine 3.0 ml. Polyoxyethylcne (in. wt.4000) 1.0 g. Hexylene glycol 10.0 ml. A S-pyrazolone coupler of U.S.Pat. No. 3,152,896 1.67 g. Sodium hydroxide 0.32 g. Water to make 1liter The bleach solution is a conventional alkali metal bromide andalkali metal ferricyanide bleach, and the hypo-fix a conventional alkalimetal thiosulfate fixing bath. A comparison of processed Film Sample Igiven the prior art process with Film Sample 11 given our process showsthat our process produces better color reproductions of the originalstep tablet than the prior art process with brighter blue images.Example 2 Example 1 is repeated, but comparing the prior art processused in Example 1 against each of five of our processes in which ColorDeveloping Agents 2, 3, 4, 5 and 6, respectively, are substituted inequimolar amounts for Color Developing Agent 1 in the yellow developingcomposition. In each instance, our processes produce color reproductionsthat are superior to the reproduction produced by the prior art processwith brighter blue images. Example 3 Two samples, I and II, of amultilayer, multicolor photographic element which element produces aninterimage effect comprising a cellulose acetate film support coated insuccession with a red-sensitive gelatino silver bromoiodide emulsionlayer (with 6 mole percent iodide) containing a mixture of nondiffusiblecyan dye-forming couplers, i.e., a naphthamide coupler of U.S. Pat. No.2,474,293 and a phenol coupler of U.S. Pat. No. 2,895,826, agreen-sensitive gelatino silver bromoiodide emulsion layer (with 6 molepercent iodide) containing 21 nondiffusible S-pyrazolone magentadye-forming coupler of U.S. Pat. No. 2,908,573 and a blue-sensitivegelatino silver bromoiodide emulsion layer (with 6 mole percent iodide)containing a nondiffusible a-pivalyl-a-phenoxyacetanilide yellowdye-forming coupler of U.S. Pat. No. 3,408,194 are sensitometricallyexposed. Sample I of the exposed film is processed at 38 C through theprior art process described in Example 2 ofHenn et al. U.S. Pat. No.2,984,567, but using in place of the reference color developingsolution, a solution having the composition:

Sodium sulfite Trisodium phosphate 12H ON-ethyl-N-(B-methanesulfonamidoethyl)- 3-methyl-p-phenylenediamine 1Citrazinic acid 1. Dithiooctanediol 1. Water to 1 pH 1 Sample 11 of theexposed film is processed through our process which is the same as theprocess used for Sample I, excepting that the 10.5 g/l ofN-ethyl-N-(Bmethylsulfonamidoethyl)-3- methylp-phenylenediamine isreplaced by 14 g/l of N-ethyl-N-methoxyethyl-3-methyl-p-phenylenediamine. The Dmax values determinedfor the processed films are summarized in the following table.

Prior art 2.9 Our process 3.3

The results show that our process produces higher Dmaxs than the priorart process for each of the image dyes. Example 4 Two samples, 111 andIV, of the multilayer, multicolor element described in Example 3 areeach given an exposure that is used to check for interimage effects. Theexposure comprises a stepped exposure to red light, superimposed by astepped exposure to blue light and a flash to green light. ExposedSample III is given the prior art process described in Example 3 forSample I and exposed Sample IV is given our process described in Example3 for Sample II. A comparison of the density vs. exposure curves plottedfor the processed films shows that the unwanted green light absorptionin the cyan and yellow dye images is corrected in Sample IV with ourprocess while the unwanted light absorptions are undercorrected by aconsiderable amount in Sample III with the prior art process. Example 5A multilayer, multicolor photographic element like the element describedin Example 3, except that a nondiffusible phenol cyan-dye-formingcoupler of U.S. Pat. No. 2,423,730 is used in the red-sensitive layerand a nondiffusible aacylacetamide yellow-dye-forming coupler is used inthe bluesensitive layer in place of the cyan couplers and the yellowcoupler used in Example 3, is made. Samples I and II of this element areexposed as described in Example 4. Exposed Samples I and II areprocessed with the prior art process and with our process, each asdescribed in Example 3. A comparison of the density vs. exposure curvesplotted for the processed films shows that the unwanted green lightabsorption in the cyan and yellow dye images is corrected by enhancementwith our process of the interimage effect while the unwanted lightabsorptions are undercorrected by a considerably amount with the priorart process. Example 6 Four samples, identified as V, VI, VII and VIII,of the multilayer, multicolor photographic element described in Example3 are sensitometrically exposed to a step tablet and processed. SamplesV and VI are processed in the prior art process described in Example 3with the color developing solution pH adjusted at 10.4 for Sample V andadjusted at l 1.6 for Sample VI. Samples VII and VIII are processed inour process described in Example 3 with the color developer pH adjustedat 10.4 for Sample VII and at 1 1.6 for Sample VIII. The change indeveloped cyan dye density, caused by increasing the pH of the colordeveloper from 10.4 to 1 1.6 at an exposure level that gives a cyandensity between 1 and 2 at a pH of 10.4, is determined for each process.This is repeated for the developed yellow dye and the developed magentadye. The results are summarized in the following table.

TABLE 7 Change in Developed Dye Density Caused by Increasing ColorDeveloper pH from 10.4

The results show that over the pH range tested, our process producesless dye density change at a given exposure level and is, therefore,less pH-sensitive than the prior art process.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

We claim:

1. In a color photographic process for treating an imagewise exposedmulticolor photographic element comprising a transparent film supporthaving coated thereon silver halide emulsion layers sensitive to atleast two of the red, green and blue areas of the visible spectrum andblack-and-white developing said silver halide emulsion layers to silverimages in areas of exposure to produce interimage effects, theimprovement which comprises enhancing said interimage effects by colordeveloping resulting undeveloped silver halide in the presence ofphotographic couplers to form nondiffusible dyes substantiallycomplementary to the sensitivity of the respective silver halideemulsion layers in an aqueous alkaline color developing compositioncontaining a color developing agent selected from the group consistingof a 3-alkly-N-alkyl-N-alkoxyalkyl-p-phenylenediamine and a3-alkoxy-N-alkyl-N-alkoxyalkyl-p-phenylenediamine.

2. The process of claim 1 wherein the silver halide emulsions are silverbromoiodide emulsions.

3. The process of claim 1 wherein nondiffusible cyan, magenta andyellow-forming photographic couplers are incorporated in the red, greenand blue-sensitive silver halide emulsion layers, respectively.

4. The process of claim 1 wherein the black-and-white developing iscarried out with an aqueous alkaline developing composition containingat least one developing agent selected from the class consisting ofhydroquinone, pmethylaminophenol, l-phenyl-3-pyrazolidone and 4,4-dimethyl-l-phenyl-pyrazolidone.

5. In a color photographic process for treating an imagewise exposedmulticolor, multilayer photographic element comprising a transparentfilm support having coated thereon red, green and blue-sensitive silverbromoiodide emulsion layers and black-and-white developing said silverbromoiodide emulsion layers to silver images in areas of exposure toproduce interimage effects, the improvement which comprises 1) makingresidual unexposed and undeveloped silver bromoiodide developable and(2) thereafter enhancing said interimage effects by color developingsaid undeveloped silver bromoiodide in the presence of photographiccouplers to form nondiffusible dyes substantially complementary to thesensitivity of the respective silver bromoiodide emulsion layers in anaqueous alkaline color developing composition containing a colordeveloping agent having the formula:

IIIH2 wherein n is an integer of 2 to 4; R is an alkyl group having oneto four carbon atoms, and R is an alkyl group having one to four carbonatoms or an alkoxy group having one to four carbon atoms.

6. The process of claim 1 wherein said light-sensitive layers of saidblack-and-white developed photographic element are 2. treating saidelement with an aqueous alkaline cyan color developing compositioncontaining a diffusible cyan-dyeforming coupler and an aromatic primaryamine color developing agent which develops said developable silverhalide in said red-sensitive layer to a silver image and a correspondingimage-wise pattern of oxidized color developing agent which reacts withsaid cyan-dye-forming coupler to form a corresponding nondiffusible cyandye image,

3. selectively treating said blue-sensitive layer to make residualundeveloped silver halide developable,

4. treating said element with an aqueous alkaline yellow colordeveloping composition containing a diffusible yellow-dye-formingcoupler and an aromatic primary amine color developing agent whichdevelops said developable silver halide in said blue-sensitive layer toa silver image and a corresponding image-wise pattern of oxidized colordeveloping agent which reacts with said yellow-dye-forming coupler toform a corresponding nondiffusible yellow dye image,

I 5. selectively treating said green-sensitive layer to make residualundeveloped silver halide developable,

6. treating said element with an aqueous alkaline magenta colordeveloping composition containing a diffusible magenta-dye-formingcoupler and an aromatic primary amine color developing agent whichdevelops said developable silver halide in said greemsensitive layer toa silver image and a corresponding image-wise pattern of oxidized colordeveloping agent which reacts with said magenta-dye-forming coupler toform a corresponding nonditfusible magenta dye image, such that at leastone of said color developing composisitions contains as the colordeveloping agent a compound having the formula:

wherein n is an integer of2 to 4; R is an alkyl group having one to fourcarbon atoms, and R is an alkyl group having one to four carbon atoms oran alkoxy group having one to four carbon atoms.

7. The process of claim 6 in which said yellow color developingcomposition contains a diffusible acylacetanilide yellow-dye-formingcoupler and a color developing agent selected from those having theformula:

acetanilide yellow-dye-forming coupler and a color developing agentselected from those having the formula:

9. The process of claim 6 in which said yellow color developingcomposition contains a diffusible acylacetanilide yellow-dye-formingcoupler and a color developing agent selected from the class consistingof N-ethyl-N-methoxyethyl- 3-methyl-p-phenylenediamine,N-ethyl-N-methoxybutyl-3- methyl-p-phenylenediamine,N-ethyl-N-ethoxyethyl-3- methyl-p-phenylenediamine,N-ethyl-N-methoxyethyl-3- propyl-p-phenylenediamine,N-ethyl-N-methoxyethyl-3- methoxy-p-phenylenediamine andN-ethyl-N-butoxyethyl-3- methyl-p-phenylenediamine.

10. The process of claim 6 in which said yellow color developingcomposition contains a diffusible acylacetanilide yellow-dye-formingcoupler and N-ethyl-N-methoxyethyl-3- methyl-p-phenylenediamine.

11. The process of claim 6 in which said yellow color developingcomposition contains a diifusible acylacetanilide yellow-dye-formingcoupler and N-ethyl-N-methoxyethyl-3- methoxy-p-phenylenediamine.

12. The process of claim 6 wherein nondiffusible cyan, magenta andyellow-forming photographic couplers are incorporated in the red, greenand blue-sensitive silver bromoiodide emulsion layers, respectively, andsaid cyan coupler is selected from the class consisting of a phenol anda naphthol; said magenta coupler is a S-pyrazolone coupler and saidyellow coupler is an acylacetacetamide.

13. The process of claim 5 wherein at least one of said silverbromoiodide emulsion layers contains at least 1 mole percent more iodidethan at least one of the other silver bromoiodide emulsion layers.

14. The process of claim 5 wherein said silver bromoiodide emulsionlayers contain in the range of from about 1 to 20 mole percent iodideand at least one of said silver bromoiodide emulsion layers contains atleast one mole percent more iodide than at least one of the other silverbromoiodide emulsion layers.

15. The process of claim 5 wherein said silver images are formed in theblack-and-white development step in the presence of a diffusible4-thiazoline-2-thione, whereby interimage effects are obtained.

16. The process of claim 5 wherein the color developing agent isselected from the group consisting of:

N-Ethyl-N-methoxyethyl-3-methyl-p-phenylenediamine,

N-Ethyl-N-methoxybutyl-3-methyl-p-phcnylenediamine,

N-Ethyl-N-ethoxyethyl-3-methyl-p-phenylenediamine,

N-Ethyl-N-methoxyethyl-3-n-propyl-p-phenylenediamine,

N-Ethyl-N-methoxyethyl-3-methoxy-p-phenylenediamine andN-Ethyl-N-butoxyethyl-3-methyl-p-phenylenediamine.

Disclaimer 3,658,525.Ri0ha1-0l L. Bent and Rowland G. Mowney, Rochester,N .Y. REVERSAL COLOR PHOTOGRAPHIC PROCESSES. Patent dated Apr. 25, 1972.Disclaimer filed Oct. 15, 1974:, by the assignee, Eastman Kodak Company.

Hereby disclaims the entire remaining term of said patent.

[Oficz'al Gazette April 8, 1.975.]

2. The process of claim 1 wherein the silver halide emulsions are silverbromoiodide emulsions.
 2. treating said element with an aqueous alkalinecyan color developing composition containing a diffusiblecyan-dye-forming coupler and an aromatic primary amine color developingagent which develops said developable silver halide in saidred-sensitive layer to a silver image and a corresponding image-wisepattern of oxidized color developing agent which reacts with saidcyan-dye-forming coupler to form a corresponding nondiffusible cyan dyeimage,
 3. selectively treating said blue-sensitive layer to makeresidual undeveloped silver halide developable,
 3. THe process of claim1 wherein nondiffusible cyan, magenta and yellow-forming photographiccouplers are incorporated in the red, green and blue-sensitive silverhalide emulsion layers, respectively.
 4. The process of claim 1 whereinthe black-and-white developing is carried out with an aqueous alkalinedeveloping composition containing at least one developing agent selectedfrom the class consisting of hydroquinone, p-methylaminophenol,1-phenyl-3-pyrazolidone and 4,4-dimethyl-1-phenyl-3-pyrazolidone. 4.treating said element with an aqueous alkaline yellow color developingcomposition containing a diffusible yellow-dye-forming coupler and anaromatic primary amine color developing agent which develops saiddevelopable silver halide in said blue-sensitive layer to a silver imageand a corresponding image-wise pattern of oxidized color developingagent which reacts with said yellow-dye-forming coupler to form acorresponding nondiffusible yellow dye image,
 5. selectively treatingsaid green-sensitive layer to make residual undeveloped silver halidedevelopable,
 5. In a color photographic process for treating animage-wise exposed multicolor, multilayer photographic elementcomprising a transparent film support having coated thereon red, greenand blue-sensitive silver bromoiodide emulsion layers andblack-and-white developing said silver bromoiodide emulsion layers tosilver images in areas of exposure to produce interimage effects, theimprovement which comprises (1) making residual unexposed andundeveloped silver bromoiodide developable and (2) thereafter enhancingsaid interimage effects by color developing said undeveloped silverbromoiodide in the presence of photographic couplers to formnondiffusible dyes substantially complementary to the sensitivity of therespective silver bromoiodide emulsion layers in an aqueous alkalinecolor developing composition containing a color developing agent havingthe formula:
 6. treating said element with an aqueous alkaline magentacolor developing composition containing a diffusible magenta-dye-formingcoupler and an aromatic primary amine color developing agent whichdevelops said developable silver halide in said green-sensitive layer toa silver image and a corresponding image-wise pattern of oxidized colordeveloping agent which reacts with said magenta-dye-forming coupler toform a corresponding nondiffusible magenta dye image, such that at leastone of said color developing composisitions contains as the colordeveloping agent a compound having the formula:
 6. The process of claim1 wherein said light-sensitive layers of said black-and-white developedphotographic element are sequentially treated to make residualundeveloped silver halide in one layer at a time developable and thenbefore silver halide in another layer is made developable, color developsaid layer initially made developable with an aqueous alkaline colordeveloping composition containing a color developing agent and adiffusible color-forming coupler which reacts with oxidized colordeveloping agent to form a nondiffusible dye, said process after theblack-and-white development comprising:
 7. The process of claim 6 inwhich said yellow color developing composition contains a diffusibleacylacetanilide yellow-dye-forming coupler and a color developing agentselected from those having the formula:
 8. The process of claim 6 inwhich said yellow color developing composition contains a diffusibleAlpha -pivalyl acetanilide yellow-dye-forming coupler and a colordeveloping agent selected from those having the formula:
 9. The processof claim 6 in which said yellow color developing composition contains adiffusible acylacetanilide yellow-dye-forming coupler and a colordeveloping agent selected from the class consisting ofN-ethyl-N-methoxyethyl-3-methyl-p-phenylenediamine,N-ethyl-N-methoxybutyl-3-methyl-p-phenylenediamine,N-ethyl-N-ethoxyethyl-3-methyl-p-phenylenediamine,N-ethyl-N-methoxyethyl-3-propyl-p-phenylenediamine,N-ethyl-N-methoxyethyl-3-methoxy-p-phenylenediamine andN-ethyl-N-butoxyethyl-3-methyl-p-phenylenediamine.
 10. The process ofclaim 6 in which said yellow color developing composition contains adiffusible acylacetanilide yellow-dye-forming coupler andN-ethyl-N-methoxyethyl-3-methyl-p-phenylenediamine.
 11. The process ofclaim 6 in which said yellow color developing composition contains adiffusible acylacetanilide yellow-dye-forming coupler andN-ethyl-N-methoxyethyl-3-methoxy-p-phenylenediamine.
 12. The process ofclaim 6 wherein nondiffusible cyan, magenta and yellow-formingphotographic couplers are incorporated in the red, green andblue-sensitive silver bromoiodide emulsion layers, respectively, andsaid cyan coupler is selected from the class consisting of a phenol anda naphthol; said magenta coupler is a 5-pyrazolone coupler and saidyellow coupler is an acylacetacetamide.
 13. The process of claim 5wherein at least one of said silver bromoiodide emulsion layers containsat least 1 mole percent more iodide than at least one of the othersilver bromoiodide emulsion layers.
 14. The process of claim 5 whereinsaid silver bromoiodide emulsion layers contain in the range of fromabout 1 to 20 mole percent iodide and at least one of said silverbromoiodide emulsion layers contains at least one mole percent moreiodide than at least one of the other silver bromoiodide emulsionlayers.
 15. The process of claim 5 wherein said silver images are formedin the black-and-white development step in the presence of a diffusible4-thiazoline-2-thione, whereby interimage effects are obtained.
 16. Theprocess of claim 5 wherein the color developing agent is selected fromthe group consisting of:N-Ethyl-N-methoxyethyl-3-methyl-p-phenylenediamine,N-Ethyl-N-methoxybutyl-3-methyl-p-phenylenediamine,N-Ethyl-N-ethoxyethyl-3-methyl-p-phenylenediamine,N-Ethyl-N-methoxyethyl-3-n-propyl-p-phenylenediamine,N-Ethyl-N-methoxyethyl-3-methoxy-p-phenylenediamine andN-Ethyl-N-butoxyethyl-3-methyl-p-phenylenediamine.